A primary objective of the beneficiation process is to reduce the silica content in the ore, as the latter reacts with caustic soda during the digestion step to precipitate out as insoluble sodium aluminium silicates, e.g. 2Na20.2 Al2O3.3 SiO2.2 H2O. This salt is eliminated from the process along with the insoluble iron and titanium oxides in red mud, consequently entailing the loss of valuable alumina and caustic soda from the process
